Recently, with LED of which the use is expanding greatly, the problem is how to sustain long the initial brightness of LED.
The cause of brightness reduction in LED is the reduction in the reflectivity of the constitutive LED reflector owing to heat discoloration thereof, and use of a material that may discolor little by heat is a factor of life prolongation of LED.
Heretofore, there is known a ceramic LED reflector that has good heat discoloration resistance (for example, see Patent Reference 1). However, ceramics are limited in point of the workability thereof and are expensive, and therefore has a problem in that they are unsuitable for general-purpose LED reflectors.
Given the situation, for a general-purpose reflector for LED as a light source to replace a fluorescent lamp, an incandescent lamp and others, used are nylon and polyamide resin that have heretofore been known also for lighting systems (for example, see Patent References 2 to 4). These have relatively good heat resistance and are inexpensive.